diff --git a/.changeset/quick-eyes-count.md b/.changeset/quick-eyes-count.md
new file mode 100644
index 000000000..39ca66536
--- /dev/null
+++ b/.changeset/quick-eyes-count.md
@@ -0,0 +1,5 @@
+---
+'slate-react': patch
+---
+
+bugfix: slate breaks on load on safari < 16.4
diff --git a/packages/slate-react/src/utils/environment.ts b/packages/slate-react/src/utils/environment.ts
index 952022957..f5727f8e2 100644
--- a/packages/slate-react/src/utils/environment.ts
+++ b/packages/slate-react/src/utils/environment.ts
@@ -55,7 +55,8 @@ export const IS_UC_MOBILE =
 // Wechat browser (not including mac wechat)
 export const IS_WECHATBROWSER =
   typeof navigator !== 'undefined' &&
-  /.*(?<!Mac)Wechat/.test(navigator.userAgent)
+  /.*Wechat/.test(navigator.userAgent) &&
+  !/.*MacWechat/.test(navigator.userAgent) // avoid lookbehind (buggy in safari < 16.4)
 
 // Check if DOM is available as React does internally.
 // https://github.com/facebook/react/blob/master/packages/shared/ExecutionEnvironment.js